These ice booms have rattled houses in
Georgia, caused the earth to shake in
Montreal, and led law enforcement from several Oklahoma
counties on an unfruitful
search to locate the ruckus.

"It was this very loud boom that happened all of a
sudden," Marjorie in Idaho, who asked that her last name be
withheld, told RT. "My son and I went to look to see where it
came from. It sounded like a door slamming very hard or something
big falling down on the patio. But we couldn’t find anything. We
watched the news later to see if anyone knew what it was, but no
one did.”

“It was so loud the house shook. My kids ran in yelling,
‘what was that mommy?’” Tracy Walker, of Kennesaw County,
Georgia, told
WAGA.

Residents in these areas thought the booms could be fireworks,
gun shots, or blown transformers. But meteorologists have offered
a less threatening, more fascinating explanation.

A ‘frost quake’ is what’s known as a cryoseismic boom, which
happens when temperatures rapidly fall below freezing after a
rainfall.

"All of a sudden that ice starts to expand — it's like having
a lid on top of a bottle, that pressure builds and builds until
finally something gives, the ice expands, the pressure is
released, the ground cracks and we hear what sounds or even feels
like a very localized earthquake,"
said Jay Scotland, meteorologist for CBC in Toronto.

"This is not an earthquake. It's ice expanding under the
ground, and it leads to a loud boom and gets folks pretty scared
when it happens in the middle of the night. Very rare, very cool
but very scary."

“The pressure grows until it breaks out and is
released,”
said David Phillips, a senior climatologist at Environment
Canada. “That's the big boom. It's all that energy.”

According to The Weather Channel’s
website, cryoseismic booms are “generally harmless,
causing nothing more than small cracks in the ground and a bit of
confusion” from people nearby.

Yet National Weather Service meteorologist Matthew Day told the
Associated Press he’s not completely convinced the booms heard
around North America are part of cryoseismic activity.

“There are some stories going around that’s what it was, but
based on the research we’ve done here, it doesn’t appear what
people heard is related to the cryoseism phenomena,” he
said. “There’s not enough moisture, and the temperatures are
not cold enough. That happens in areas where you have a lot of
water flowing through a lot of rock.”

But he added that he does not have an explanation for what,
exactly, causes the ice booms.